diff --git a/src/wp-includes/class-http.php b/src/wp-includes/class-http.php
index d947bcac1b..ff69de3635 100644
--- a/src/wp-includes/class-http.php
+++ b/src/wp-includes/class-http.php
@@ -20,6 +20,67 @@
  */
 class WP_Http {
 
+	// Aliases for HTTP response codes.
+	const OK                              = 200;
+	const CREATED                         = 201;
+	const ACCEPTED                        = 202;
+	const NON_AUTHORITATIVE_INFORMATION   = 203;
+	const NO_CONTENT                      = 204;
+	const RESET_CONTENT                   = 205;
+	const PARTIAL_CONTENT                 = 206;
+	const MULTI_STATUS                    = 207;
+	const IM_USED                         = 226;
+
+	const MULTIPLE_CHOICES                = 300;
+	const MOVED_PERMANENTLY               = 301;
+	const FOUND                           = 302;
+	const SEE_OTHER                       = 303;
+	const NOT_MODIFIED                    = 304;
+	const USE_PROXY                       = 305;
+	const RESERVED                        = 306;
+	const TEMPORARY_REDIRECT              = 307;
+	const PERMANENT_REDIRECT              = 308;
+
+	const BAD_REQUEST                     = 400;
+	const UNAUTHORIZED                    = 401;
+	const PAYMENT_REQUIRED                = 402;
+	const FORBIDDEN                       = 403;
+	const NOT_FOUND                       = 404;
+	const METHOD_NOT_ALLOWED              = 405;
+	const NOT_ACCEPTABLE                  = 406;
+	const PROXY_AUTHENTICATION_REQUIRED   = 407;
+	const REQUEST_TIMEOUT                 = 408;
+	const CONFLICT                        = 409;
+	const GONE                            = 410;
+	const LENGTH_REQUIRED                 = 411;
+	const PRECONDITION_FAILED             = 412;
+	const REQUEST_ENTITY_TOO_LARGE        = 413;
+	const REQUEST_URI_TOO_LONG            = 414;
+	const UNSUPPORTED_MEDIA_TYPE          = 415;
+	const REQUESTED_RANGE_NOT_SATISFIABLE = 416;
+	const EXPECTATION_FAILED              = 417;
+	const IM_A_TEAPOT                     = 418;
+	const MISDIRECTED_REQUEST             = 421;
+	const UNPROCESSABLE_ENTITY            = 422;
+	const LOCKED                          = 423;
+	const FAILED_DEPENDENCY               = 424;
+	const UPGRADE_REQUIRED                = 426;
+	const PRECONDITION_REQUIRED           = 428;
+	const TOO_MANY_REQUESTS               = 429;
+	const REQUEST_HEADER_FIELDS_TOO_LARGE = 431;
+	const UNAVAILABLE_FOR_LEGAL_REASONS   = 451;
+
+	const INTERNAL_SERVER_ERROR           = 500;
+	const NOT_IMPLEMENTED                 = 501;
+	const BAD_GATEWAY                     = 502;
+	const SERVICE_UNAVAILABLE             = 503;
+	const GATEWAY_TIMEOUT                 = 504;
+	const HTTP_VERSION_NOT_SUPPORTED      = 505;
+	const VARIANT_ALSO_NEGOTIATES         = 506;
+	const INSUFFICIENT_STORAGE            = 507;
+	const NOT_EXTENDED                    = 510;
+	const NETWORK_AUTHENTICATION_REQUIRED = 511;
+
 	/**
 	 * Send an HTTP request to a URI.
 	 *